Reaching a crossroads

Ive been lifting weights for some while now, most recently i used NO Xplode with Prolab N Large2 and my results are not what i was hoping for, sure i have got good strength gains but my mass gains are lagging behind. I train intensly with good form, eat as much as i can, but my training partner has got far superior gains with what looks like less effort, its very ****ing annoying, i was wondering if anyone could give me advice with either supplementation or if i should head down a different avenue?